Apparatus for handling contact masses



July 8, 1947 c. H. LECIHTHALER Erm. 2,423,813,l

y APPARATUS FOR HANDLING CONTACT MASSES Filed April 15, 1943 3sheets-sheet 2 J4 if? ,I

. 4 d'5 DusTJ'EpARATo/z "y Zossen 15 lNvENroR Jl July 8 1947- c. H.LECHTHALER E TAL 2,423,813

A PPARATUS FORfHANDLING CONTACT MASSES Filed April 15, 1943 v s'Sheets-sheet s C'f/mu fa/Music 20.1.1: LL. EL

lNvENroR 5 Patented July 8, 1947 2,423,813 APPARATUS FOR HANDLINGCONTACT l MASSES Charles H. Lechthaler, Woodbury, and Russell Lee,Mantua, N. J., assignors to Socony-Vacuum New York Oil Company,Incorporated,l a corporation of Application April 15, 1943,` Serial No.483,120

s '4 claims. (ci. zs-zss) y In the catalytic treatment of hydrocarbons,for such purposes as cracking high boiling hydrocarbons to gasollnes,and for similar purposes, recently developed processes have made use ofcatalytic contact masses comprising formed particles or granules ofalumina-silica complexes, and similar materials, such as fullers earth,Filtrol, and other natural clays, including altered and activatednatural clays, synthetic composite particles arising from gels, and thelike. These solid adsorptive catalytic materials are spoken oi' broadlyunder the term clay type contact mass materials.

In the flrst commercialization of catalytic cracking, the contact masseswere composed ol?` particle form clay type materials utilized asbeds-in-place alternately subjected to reaction and to a combustionregeneration `for the purpose of removing carbonaceous deposits placedpeilets or granules of about 30 mesh per inch size or larger, there is acertain production of fines, as by attrition, etc. With such processesemploying particles of appreciable size, the contact of reagent andcontact mass, or of regeneration agent and contact mass is achieved byflowing the iluid reagents or regenerant through the interstiees in themoving bed of contact mass. Fines of contact mass material give rise totrouble when present in excess amounts.

This invention has for its object the removal of ilnes of contactmass'material from processes wherein a particle-form solid contact massmaterial having appreciable particle sizes, say above about 30 mesh, iscyclically moved through a re'- When the contact Amass particles are ofappreciable size such as yical difficulties because of hightemperatures.

tremely small particles when Present in small' concentration, is notapplicable to what is really a problem of size separation. 'I'hisinvention has applied, in a specific manner, the process of elutriation,that is, contact of a particle stream with countercurrently ilowinggases at rates designed to remove all particles smaller than a desiredsize.

In order to conveniently understand the invention, reference is now madeto the drawings attached hereto. In these drawings, Figure 1 serves toshow, dlagrammatically. the surroundings in which the invention ispractised. Figure 2 shows in diagram form a vertical section ofapparatus appropriate for its practise, Figure 3 shows 4a plan view oftheapparatus of Figure 2, Figures 4 and 5 show a detail therein, andFigures 6 and 7 show an optional form for that detail.

In Figure 1, item I0 is a reactor through which a stream of contact massparticles passes in a downward direction to be contacted with hydro-vcarbon reactants introduced by pipe II and removed by pipe I2. Spentcontact mass material passes from the reactor through duct I3 and islelevated by elevator I4 to pass through duct I5 into the upper end of aregenerating kiln I6. In this re'generatingixn I6 regeneration medium,

^ usually air, is i'ed by pipe Il through orifices I8 y lected into eachof two ducts 20 and pass up-b wardly. Above kiln I6 there is a finescleaning device composed substantially of a vertical member 2i, which isdescribed later in more detail.

action zone where hydrocarbon reaction is conducted, thence through aregenerating zone, and i then returned to reaction.

Separation of ilne particles from coarse particles oi' solid may beconducted in several different ways, as by screening, use of centrifugalforce, electrical precipitations, or elutriation. In the surroundingsspoken of the application of any screening method is open to manymechan- By' means of ducts 22 and dampers 23, a portion of the ilue gasis forced to ilow into cleaning column 2i, the remainder passingupwardly to enter a final separator 24 by means of ducts 2l. Flue gasesfrom cleaning column 2| pass through ducts 26 into ducts 20 to similarlyenter separator 24. These flue gases from 2i contain the fines cleanedfrom the contact mass material. All nes separatedin 24 are dischargedfrom the system through pipe 21, clean ilus gases being discharged toatmosphere through pipe 2B. The regenerated contact mass materialflowing from the bottom of kiln I8 through duct 28 is elevated byelevator 30 and discharged through 3 duct 3| linto a storage hopper 32from whence it iiows by duct 33 into reactor I0. A portion of thisregenerated material is conducted by duct 34 to cleaning column 2|. Theportion selected for cleaning may be taken either from the regenterialflowing through duct lli. In general. it is preferred to work withregenerated material for various reasons, such as for example, it iseasier to handle in cleaning, and this choice is usually reenforced bynot having to build the spent catalyst elevator I4 sufficiently great inheight to give access to the top of cleaning column 2 I.

Turning now to Figure 2, We have a detail showing the top of theregenerator kiln IB into which contact mass material has been fed byduct II and from which there extends upwardly the cleaning column 2|. Aportion of the contact mass material is fed through duct 34 to the topof 2|, the amount so fed being controlled by a sliding orifice plate orother appropriate type of valve 35. Inwardly of column 2|, duct 34termi.. nates in a feed pipe 36 below which there is positioned adistributing cone 31 so that the contact mass particles are distributeduniformly in a shower in the interior of cleaning column 2|. Cleanedmaterial from the bottom of 2| passes through pipe 38 into the interiorof kiln-I6. this pipe terminating in a cone 39 at a point below thelevel of contact mass material in the kiln as designated by line 40.Flue gas from kiln I6 is introduced into cleaning column 2| by means oi'ducts 22 which lead into a pressure chamber 4| surrounding the cleaningcolumn near its bot- Y tom, the Wall of the column being perforated byorifices 42 so that a uniform and proper distribu- .tion of gas into thecleaning column 2| may be erated material, as shown, or from the spentma- Figure 3 is a plan view of the apparatus shown i in Figure 2,serving merely to indicate its general arrangement. In this figure, i6is the regenerator, I5 the feed duct therefor, 2| is the cleaningcolumn, 34 is the pipe feeding solids thereto. 35 the valve in that feedpipe, 4| the inlet gas pressure chamber, 22 and 22 the inlet gas feedducts, 2B and 26 the outlet gas ducts, 24 the separator, 25 and 25 ductsleading flue gas thereinto and 28 the stack of the separator.

In Figures 4 and 5, which/should be read together, we find a detail ofthe arrangements for f introducing contact mass material in a uniformmanner to the cleaning column 2|. In the column 2| the feed pipe 36 iscentrally located extending therein to a depth indicated by line A,

suiiicient to permit a reasonable collection space for discharged gasesabove the point of contact mass introduction. Just below the end of pipe36 there is mounted distributor cone 31 which, by experiment, has beenfound to be preferably a cone having .45 sides and a base diameter aboutone-third the diameter of the cleaning column 2|, so mounted that itsapex is practically at the level A. (The slope of the cone will dependsome-v what upon the nature of the solid material being handled.)Additionally, this cone is provided with certain orifices 43, the numberand size of these orifices being so selected that a portion of thecontact mass material flowing over the surface of the cone is dischargedtherethrough to provide about the same mass velocity ofcon- Aupwardlyascending stream of gas.

1 36. that pipe is divided into several pipes 44. each with its own cone45, these pipes and cones being so arranged as to secure a substantiallyuniform distribution over the entire area of cleaning column 2|.

In this cleaning column, the method of cleaning is by conducting afalling shower of contact `mass particles including fines with anupwardly ascending column of gases of predetermined velocity sufficientto sweep from that column of particles all particles finer than acertain predetermined size.

In application to the present operation in which this method of cleaningis applied, wherein we are circulating a stream of contact massparticles continuously through two zones, in one of which they arecontaminated by reaction and in the other of which they are regeneratedby combustion, we segregate a relatively quite small portion of thecirculating stream of contact mass material, scrub it with a portion ofthe flue gases from regeneration, return the scrubbed 'stream of contactmass material to cycle and discharge the flue gases, after separatingand discarding iines therefrom, to the atmosphere.

There are two fundamental controls for this operation. The first is thatof gas velocity in the This is so adjusted as to be maintained slightlyabove the "terminal velocity for the largest particle to be eliminated.Terminal velocity may be dened as that velocity of gas which willprevent the falling of a selected particle.

For catalyst particles ranging in size from 14 to mesh (Tyler scale) influe gas at 800-l100 F. and atmospheric pressure, terminal velocity isexpressed by the Allen-Glazebrook equation as:

V: acosta-2- g Where: V=terminai velocity in cm./sec.,

( :the critical radius of the particle above which Stokes Law is notobeyed, 9 v2 l a =radius of the particle in cm.,

v =kinematc viscosity ofl the fluid, in Stokes,

Reduced to concrete terms in an example, to remove particles of 35 meshand finer having a specific gravity of 1.45, when the fluid supportingmedium is flue gas at 900 F. and atmospheric pressure, the velocityshould be 8.2 feet per second. With this velocity, the separatedcatalyst nes will be found to be of all sizes up to and includirig 35mesh, the bulk of them being below y circulating may be increased ordecreased by in-4 creasing or decreasing the proportion subjected tocleaning. Greatest efficiencies of removal are obtained when the amountof material subjected to cleaning does not exceed 1 ton/hr. per sq. ft.of cleaning column cross sectional area. The actual amount so subjectedis found to be quite small. For example, in a unit circulating 100 tonsper hour, only 5 tons per hour need be subjected to cleaning in order tohave the whole substantially free of lines, when the contact massparticles have the resistance to attrition ordinarily characteristic ofpelletted clays. This figure will vary, of course, with the resistanceof the contact mass to attrition, since less resistant particles willgive rise to more fines and will require that a greater proportion besubjected to cleaning to secure equal freedom from lne particles.

We claim:

l. In a system for the conversion of hydrocarbons in the presence of aparticle form solid contact mass material a reaction zone, means tointroduce particle form solid contact mass material thereto and means toremove it therefrom, means to introduce hydrocarbon reactants theretoand means t0 remove hydrocarbon reaction products therefrom, aregeneration zone, means to introduce contact mass material thereto andmeans to remove it therefrom, means tointroduce fluid regeneratingmedium thereto and means to remove it therefrom, meansto transfer spentcontact mass from the reactor to the regenerator,

means to transfer regenerated contact mass from the regenerator to thereactor, means to divert a portion of the moving stream of contact massat a point between the regenerator and the reactor,

scrubbing means for said diverted contact mass comprising a verticalpassage, means to introduce diverted contact mass to'said passage topass 'downwardly therethrough as a showen'means to flow a gas upwardlyvthrough said passage at controlled velocity sufllcient to .remove finerparticles of contact mass from said shower, separate exit means fromsaid passage for fines-laden gas and' 4means tov introduce hydrocarbonreactants thereto and means to remove hydrocarbon reaction productstherefrom, a regeneration zone, means to introduce contact mass materialthereto and means to remove. it therefrom, means to introduce fluidregenerating medium thereto and means to remove it therefrom, means totransfer spent contact mass 'from the reactor to the regenerator, meansto transfer regenerated con tact mass from the regenerator to thereactor, means for cleaning less than all of the moving stream ofcontact mass from fines comprising a confined vertical passage, means toadmit a controlled portion of the moving stream of contact mass theretofrom a point between the reactor and the regenerator, means todistribute the con tact mass so admitted into a shower fallingsubstantially uniformly through all of the horizontal f 6 cross sectionof such passage.. means near the bottom of such passage to admit a gassubstantially uniformly to all portions of the cross section of suchpassage, means to control the amount 5 of gas so admitted to give a gasvelocity countercurrent to said shower sufnciently great to float andremove therefrom particles of less size than a selected minimum size,exit means for finesladen gas near the top of said passage, and means l0for returning only the cleaned contact mass ma- 15 troduce particle formsolid contact mass material thereto and means to remove it therefrom,means to introduce hydrocarbon reactants thereto and means to removehydrocarbon reaction products therefrom, a regeneration zone, means tointroduce contact mass material thereto and means to remove ittherefrom, means to introduce fluid regenerating medium thereto andmeans to remove it therefrom, means to transfer spent contact mass fromthe reactor to the regenerator, means to transfer regenerated contactmass from the regenerator to the reactor, means for cleaning less thanall of the moving stream of contact mass from fines comprising aconfined vertical passage, means to admit acontrolled minor portion vofo the moving stream of contact mass thereto from a point between thereactor and the regenerator, means to distribute the contact mass soadmitted into a shower falling substantially uniformly through all ofthe horizontal cross section of such passage, means to admit gas to flowupwardly through said passage at rates substantially uni.-V form acrossthe cross section thereof, means to control the amount of gas soadmitted to give a gas velocity countercurrent to said shower suf- 40flciently great to float and remove therefrom particles of less sizethan a selected minimum size, exit means for fines-laden gas near thetop of said passage, a gas-solid separator for removing fines from saidfines-laden gas, means to direct said fines-laden gas from said exitmeans to said separator, a gas outlet from said separator, an outlet forwithdrawal of said fines from said separator to a location outside ofsaid system and means for returning cleaned contact massA material tothe cycle.

. 4. In a system for the conversion of hydrocarbons in the presence of aparticle form solid contact mass material a reaction'zone, means to invtroduce particle form solid contact mass material thereto and means toremove it therefrom, means to introduce hydrocarbon reactants theretoand 6means to remove hydrocarbon reaction productsv therefrom, aregeneration zone, means to introduce contact mass material thereto andmeans to a0 remove it therefrom, means to introduce iluid regeneratingmedium thereto and means to remove it therefrom, means to transfer spentcontact mass from the reactor to the regenerator, means to transferregenerated contact mass from the lregenerator to the reactor, meanstodivert a portion of the moving stream of contact mass at a pointbetween the regenerator and the reactor, scrubbing means for saiddiverted contact mass comprising a vertical passage, means to introduce.diverted contact mass to said passage to pass downwardly therethrough asa shower, means to flow a gas upwardly through said passage atcontrolled velocity sufficient to remove finer particles of contact massfrom said shower,

76 means to divert a portion of the regenerator ef.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Name Date VDegnen July 21, 1942 Number NumberNumber Name v Date Kuhl Nov. 24,1942 Kassel July 27, 1943 Keranen Aug.3, 1943 Barnard Nov. 1, 1892 Balcom May 3, 1910 Peebles Sept. 28. 1943Degnen et a1 June 6, 1944 Hemminger Nov. 7, 1944 FOREIGN PATENTSCountry' Date Sweden Oct. 21, 1937

